Re: Inertia and third principle

This is a continuation of my previous post.

In my animation https://www.geogebra.org/m/qterew9m the action of body A and the reaction of body B occur exclusively through the two first rows, because the actions and reactions that occur behind the first row of body A are *internal* to body A and the same happens to the actions and reactions behind the front row of body B, which are internal to body B.

At instant 1, the action is +3, the reaction -3 and the two first rows stop and compress.

At instant 2, the action is +6, the reaction -6 and the first two rows of each body stop and compress more.

At instant 3, same thing: the action is +9, the reaction -9 and the first three rows of each body (9+9 particles) stop, compressing to the maximum.

Why did the compression progressively increase? Because the *internal* forces of the internal particles have *accumulated* on the first row of each of the two bodies (the place where the action and reaction take place).

Why were there these actions and these compressions? They occurred because the B corps was able to resist without retreating.

Instead, at instant 4, when the first row of body A receives a further increase in forces directed towards the right from its internal particles and increases its action from +9 to +12, on the other side there is the first row of body B which has not received any further help from its internal particles, can no longer increase its reaction from -9 to -12, must suffer the net external force +3 (+12-9) and must retreat accordingly, without being able to to oppose.

So, already here, the action of body A (+12) is greater than the reaction of body B (-9).

At instant 5, the action of body A increases even more (+15), while the reaction of body B always remains equal to -9.

Obviously, the actions and reactions don't end here because the dark area of the animation remained compressed like a spring.

And like all compressed springs, it will have to release its internal force from one side to the other.

So, there is still more to write and I cannot do it in this post which has become quite long and there is no need to make it even longer.

Furthermore, these other considerations are more than enough to reflect on while waiting for my next post, always assuming that the moderators allow me to divide my writings as I am doing.

Luigi Fortunati